However it soon became clear that the combination of enemy action, aging vehicles, and shortages of parts was affecting operators ability to maintain services. The Ministry of Supply thus allowed selected manufactures, including Guy, Bristol, Daimler and Leyland to produce bus chassis', while a limited number of bodybuilders were allowed to build bodies to a highly restrictive specification. These bodies were built using un-seasoned timber, limited interior paneling, and the design also omitted any non essential radiussed sections, allowing a saving in scarce materials and labour time. From the passengers point of view, comfort wasn't a high priority, as most of the vehicles were supplied with rather basic wooden slated seats.

These buses were allocated by the Ministry to operators on a need to have bases, with various combinations of body and chassis types appearing in many urban fleets across the country.

The poor quality materials used in the utility bodies, meant that most had a short life in their original form. During the 1950's many operators re-bodied or withdraw these vehicles has soon as possible.

The Utility type was used by London Transport between 1942 and the the early 1950's. Deliveries included 9 Bristol K5, 281 Daimler CWA6 / CWD6, and 435 Guy Arabs, some of the later deliveries had less austere styling, which allowed radiussed rear roof domes.

Virtually all the London vehicles were used on Central Area routes, although some Daimlers did find their way onto the Greenline network when it was re-introduced following its wartime suspension.

THE EFE MODELS
EFE have chosen to model four Utility types. The Guy Arab I / II, Bristol K, and Daimler CW, the difference between each of the models, is limited to the radiator, front mudguards, and bonnet area, while all versions share the same upper and main lower deck castings.

The Guy Arab II has proved the most popular version, which reflects the situation with the real vehicles. All the versions first appeared in 1999.  

EFE have a choice of two top deck castings which can be used for the Utility models, the most commonly used is the more austere version which uses two flat panels to produce the rear dome profile, the second version has a proper curved dome and a slightly larger upper deck rear window, it reflects the more relaxed design allowed by Ministry of Supply on later versions of the utility bodies, this second version has to date only been used by EFE on four model releases: 26310, 23613, 26404 & 26501.

One interesting episode involves East Yorkshire Daimler release 26404, which due to a factory error was released with a Guy Arab II radiator, this model was later re-worked and re-issued as 26313, being given a fleet number and registration used on an actual Guy vehicle in the same fleet.

Four Utility models featured in the War Time Buses Series that was released during the early Summer of 2006 to mark the 60th Anniversary of the end of World War II. These models were given their own 9920x catalogue number series and were issued in special themed packaging.